• International Journal of Aeronautical and Space Sciences
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• v.9 no.1
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• pp.162-168
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• 2008

A design objective for variable stability flight control system is to develop a controller of in-flight simulation capability that forces the aircraft being flown to follow the dynamics of other aircraft. This paper presents a model-following variable stability control system (VSS) for in-flight simulation which consists of feedforward and feedback control laws, the aircraft dynamic model to be simulated, and switching and fader logics to reduce the transient effect between two aircraft dynamics. The separate design techniques for feedforward and feedback control law proposals are based on model matching and augmented linear quadratic (LQ) techniques. The system allows pilots to select and engage VSS mode, and when deselected, the aircraft reverts to the baseline flight control system. Both the baseline flight control laws and VSS control laws are computed continuously during flight. Initialization of the state values are necessary to prevent instability, since VSS control laws have integrators and filters in longitudinal, and lateral/directional axes. This paper demonstrates and validates the effectiveness and quality of VSS with F-16 models embedded in T-50 in-flight simulation aircraft.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6243-6259
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• 2019

As a foundation of next-generation air transportation systems, automatic dependent surveillance-broadcast (ADS-B) helps pilots and air traffic controllers create a safer and more efficient national airspace system. Owing to the open communication environment, it is easy to insert fake aircraft into the system via spoofing or the insertion of false messages. Efforts have thus been made in academic research and practice in the aviation industry to ensure the security of transmission of messages of the ADS-B system. An identity-based batch verification (IBV) scheme was recently proposed to enhance the security and efficiency of the ADS-B system, but current IBV schemes are often too resource intensive because of the application of complex hash-to-point operations or bilinear pairing operations. In this paper, we propose a lightweight IBV signature scheme for the ADS-B system that is robust against adaptive chosen message attacks in the random oracle model, and ensures the security of batch message verification and against the replaying attack. The proposed IBV scheme needs only a small and constant number of point multiplication and point addition computations instead of hash-to-point or pairing operations. Detailed performance analyses were conducted to show that the proposed IBV scheme has clear advantages over prevalent schemes in terms of computational cost and transmission overhead.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.2
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• pp.71-78
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• 2020

This paper proposes vision sensors and deep learning-based around view monitoring system for ship berthing. Ship berthing to the port requires precise relative position and relative speed information between the mooring facility and the ship. For ships of Handysize or higher, the vesselships must be docked with the help of pilots and tugboats. In the case of ships handling dangerous cargo, tug boats push the ship and dock it in the port, using the distance and velocity information receiving from the berthing aid system (BAS). However, the existing BAS is very expensive and there is a limit on the size of the vessel that can be measured. Also, there is a limitation that it is difficult to measure distance and speed when there are obstacles near the port. This paper proposes a relative distance and speed estimation system that can be used as a ship berthing assist system. The proposed system is verified by comparing the performance with the existing laser-based distance and speed measurement system through the field tests at the actual port.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1871-1877
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• 2009

KORAIL has been established by 1st January 2005. From organization change to KORAIL(Korea railroad Corporation), labour union and company management team has been argument for their train crews and drivers operation system. For example, train crew and driver working conditions; working hours per week, off day and duty day time, over night time working payment, current position payment, preparation time, company own lodge operation and so on. I assure that this comparison study for train crew and driver operation between KORAIL and EWS will helps to improve other korean railway companies management efficiency. In conclusion, EWS has 4$\sim$6 times more efficient employee for active operation than KORAIL per 1 freight brock-train operation. EWS has very resonable train crews and driver operation system, and self-control regulation for employee and management team with trusty. This thesis propose that korean railway companies and their own labour unions need joint research and benchmarking other oversea railway companies as like EWS.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.912-918
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• 1994

Poor speech intelligibility in an air traffic control room is frequently a result of many, quite different causes and occasionally leads to complaints of the controller personnel. The paper describes a sequence of successful tasks performed in a local control room. The initial measurements included an investigation of the background noise (caused by fans, air condition, computer and radar equipment) and performance checks of the electronic audio and communication equipment with respect to the audio transmission behavior. The spectral composition of the noise as well as the characteristics of the audio communication path between the controllers and the pilots(which showed a loss of spectral information in the audio band due to built-in notch filters for the suppression of control tones) required adaptations of the amplitude behavior of the amplifiers through user adjustable tone controls. The radar console fans, which contributed significantly to the overall noise floor of the room, underwent a substantial reconstruction by replacing the tight mounting with an elastic double suspension, reducing the noise level by 50%. Finally, a possible source of untimely fatigue of the controllers during their working hours has been found in strong spectral components of the noise above the audio band, radiated by numerous video monitors in the control through vibrating components excited by the line frequency of the video signal.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.2
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• pp.37-48
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• 2014

Fighter squadron flight scheduling is the integrated air operation plan that is an important role for improving pilot's flight skill and maintaining combat readiness by efficient using available all air resources including pilot, aircrafts, air-weapons, fuel and supporting facilities etc. Korea airforce, however, has a limit as to an effective flight operation due to manual flight scheduling with scheduler's own experience and intuition. Therefore, in our study, we propose the optimization model of flight scheduling based on mixed integer programming. This model includes several constraints of realistic and essential quantified data related with flight schedule and can assign appropriate pilots optimally which are distinctive three type's solutions : flight, alert and duty crew schedules. Proposed solution method can be improved pilot's capability and allocated further air resources systematically and efficiently. In addition, it can be reduced a workload of flight scheduler and minimized obstructed factors of flight safety. Finally, we demonstrate the experiment's results for the check of efficiency and validity of this model.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.248-257
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• 2006

There will come someday when UAUs can fly into the airspace of manned aircraft in the near future because of the increasing number of operational UAUs together with technologies development. Since pilots of UAVs are on the gound, the equipment for sensing and avoiding obstacles in front is indispensable. In this paper, we analyze functions and interfaces of TCAS II, a collision avoidance device for manned aircraft, then find out whether it is suitable for the collision avoidance device for UAV and problems associated with it, if any. It turns out to be that the onboard directional antenna of TCAS II does not provide a precise directional information, and that the TCAS II is not assumed to be installed alone, but used as supplementary with other device which provides the better precision.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.383-386
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• 2017

Avionics, a type of embedded system, requires high safety and reliability. Failure of avionics equipment can have a significant impact on aircraft operations and, in the worst case, could result in loss of life for pilots and passengers. In this paper, we propose a Built-In-Test (hereafter referred to as BIT) design technique that can detect possible faults in avionics equipments in order to increase the reliability of avionics system and a design that can improve the Mean Time Between Failure (hereafter: MTBF) and applied it to real aviation electronic equipment to improve reliability.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.4
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• pp.87-92
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• 2014

In spite of ICAO's effort to ensure the safety of flight operation by requiring crews, controllers, and other ground aviation staffs to use unified system for units, SI (System International of units), there are still many aircrafts designed, manufactured, and operated based on non-SI units, and many crew training in airline companies are also conducted based on non-SI. Due to this confusion of using different unit systems in international flight operation, many crew members and passengers are exposed to danger. International flights pilots may have confusion while flying different airspaces of different countries that use different unit systems, and this may cause human errors causing accidents and incidents. Due to these reasons, it is needed to establish the standards to reflect non-SI that many countries practically use to SI, which is international standard.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.49-56
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• 2016

Flapper Valve of Korean Utility Helicopter(KUH-1) is an essential equipment in Environmental Control System(ECS) for pilot to perform flight mission. It provides pilots and crews with heating, ventilating and air conditioning. It has function of maintaining room temperature to sustain operational capability for pilot and crew. This paper summarizes pilot comments in flight test which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test at low temperature.